Objective. To determine whether repeated motion with low magnitude joint forces, and
flexion/extension moments consistently produce herniation in a non-degenerated, controlled
porcine spine motion segment. Design. Combined loading (flexion/extension motions and
compressive forces) was applied to in vitro porcine functional spinal units. Biomechanical
and radiographic characteristics were documented. Background. While most studies
performed in vitro have examined uniaxial or fixed position loading to older specimens …